The Stone Forest has experienced a long and complicated geological evolution. What the stone forest landform displays at present developed mainly in four geological periods: ⑴ late stage of the middle Permian (260 million years ago); ⑵late stage of the Cretaceous to the early Tertiary (80 -60million years ago); ⑶ late stage of the Tertiary (5-2 million years ago); and ⑷ the Quaternary (2 million years ago to the present).

In the middle Permian, 270 million years ago, the Shilin area was a vast sea. A carbonate deposit hundreds of meters thick formed on the ocean floor. Then 260 million years ago, the Shilin region emerged from the ocean as a result of tectonic uplift. In a humid and warm climate and coastal environment, the first stone forest landform developed on the fractured limestone. Shortly after that, extensive volcanic activity buried the Shilin area and the early stone forest under hundreds of meters of basalt. During the Mesozoic period the basalt-covered Shilin area was slowly uplifted and the basalt cover was largely stripped off by erosion. In the early Tertiary, some 60 million years ago, Himalayan orogenic movement further uplifted the Shilin area and turned it into an intra-montane paleo-lake (the present Lunan Basin). Since the late Tertiary, drastic uplift transformed the Shilin area to the present hilly plateau environment. In association with the intermittent regional uplift came the successively developed stone forest landform with new clusters replacing old ones. Over 260 million years the stone forest was twice covered (by Permian basalt and Tertiary lake sediment) and twice reemerged. Its long and complex evolution is unrivaled in the world.

Semi-weathered basalt

Permian stone-teeth re-expose from basaltic cover

Baked by basaltic lava, the Permian stone teeth are in black color

Stone forest and weathered basaltic laterite

Conglomerate of Tertiary lake sediment

Stone forests re-expose from Tertiary red beds

Lake-deposited red beds of Eocene, Eogene Period

Stone teeth and red beds

Stone forest and early Tertiary lake sediment

Stone forest and stone teeth